Improvement in bkidges



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Y Letters Patent No; 77,741, dated May 12, 1868; antcdatcd April ,98,'18-68.

IMPROVEMENT 1n BRIDGES.

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To- ALL 'WHOM 1T MAY eoNeERN: l i t t Be it known that I, GEORGE T. LAPE, of Summitin the county of' Schoharie,iin the Stateof New York,-

have invented a new and useful Improvement in the Construction ofBridges, Culverts, Tunnels, 35o.; and I do hereby declare that the following isa full, clear, and exact description thereof, enabling others `skilledin the artto make and use the same, reference being had tothe accompanying drawings, in which- Figurcl represents a Vertical projection or side view of' two sectionsor youssoirs. Figure 2, ahprizontai projection or plan of the same.

Figure 3, in which a being taken as the key of the arch, shows the 'principle of combining the sections or voussoirs by means of dove-tails, tongues, and grooves. i i t v I I s Figure 4 shows an under view or. development of several sections o r voussoirs combined. i

Figure represents cross-sections on a b and a: y.

Similargietters are used to represent similar parts throughout.

The objectof vmy invcntion is to provide a convenient and economical means of lconstructingbridges, cuiverts, and arches, and consistsi' l.

First/,in preparing a series of sections or voussoirs which, when put together,'as hereinafter described, will Iform the desired arch; and

Second, in providing a means to secure the several sections together. Havingldetermined the dimensions and form of the arch which it is desiredto construct, I cast as many of. thel sections m m as may be found necessary for the purpose offorming such arch, each section, of course, being' cast in such form that when they are secured together in their respective proper relative positions, the desired arch will bepro'dueed. i i .i l vThe sections or voussors may be of any convenient length or breadth, and the several parts of any desired thickness, all of which is to be determined by the various uses to which they are to be applied, and the required strength or capacity of-the structure.; ea'cbvoussoir or section having two abutting ends, AVA, an irregular top plate or flange, m,`in th'e form shown ih fig. 2; a cross-plate, B, running across the entire section; alongitudinal rib, n, and a bottom longitudinalilange, P, alleast, from iron or other suitable metal, in one piece. The top plate or ange is jagged each way, at the centre cross-plate, about one-fifth of its breadth, so that the abutting longitudinaljoints may be broken, as shownin fw. 2, and the centre cross-plate is groeved or tongued in the space' left -by the jogs, so that the tongue or groove of a corresponding part of an abutting section may be secured to'it. l

I The top plate or'lange, therefore, in all cases where the whole space is t-o be covered by it, wllpresent the irregular or jagged longitudinal lines, shown in said figure, while the rib n and lower flange P are cast to such irregular top plate oriange in such position that theyiwill always form a continuousv straight line throughout,

but the top plate or flange m may be variedin width according to the uses to which-the sections are to be` applied.l

For railroad-bridges this top plate or flange need he no wider than the lower Harige, the two flanges, with the rib, forming as it were an I-rail, but for-tunnelling or light purposes the top plates or flanges should, when combined, extend all the way across the structure.A

lThe centre cross-plate is employed for the several purposes of adding strength, breaking joints, and assisting in locking the sections and segments together. y

Fig. 3, which although with its lines and letters more particularly refers to the key-section of the arch, shows the principle of the construction of the tongues, grooves, and dove-tails on the severalsections, and the general manner of abutting arid securingthe sections to each other. This section, whose central radial line, :z: y, is--brought to coincido with :t v prolonged, vbeing its position whenin place in the arch,) is moved down in a direct line into its required position, while the tongues s s, on its radialabutting ends, tting into corresponding grooves rr'in the radial abutting ends of the adjacent sections, secure itin its true position. The triangle c d cor wedge-shaped tongue projects from, and thetriangleor wedge-shape groove cfg recedcs into the'radial abutting ends of adjacent sections. The triangles h ej and d 'z' c show a reverse case, while4 the rectanglesc i d e` and efhg combine the two cases, and form regular prismatic tongues and grooves, respectively projccting from or receding into the radial abutting cndstof the section..` The positions o i' these tongues s sis and grooves r r 1* inthe abutting ends andfcross-scctions of the various sections are clearly shown in tif'. 4, astbey appear respectively vcast in and upon the abutting ends of the sections, and at abutting'portion of the centre plate, some of them showing the form of the Vordinary tonguesand grooves,` and others inthe form of dove-tails.

In iig. 4, the half section b is introduced to show the manner of breaking the cross-jontsn the structure.

To ed`cct this, theright-hand abutting end of bihas the order of its grooves reversedLas will be seen by comparing it with theright-hand abutting Iend of. the adjacent left-hand section, and this order of reversal of tongues and grooves `will be necessarily continued where a half sectionfis introduced for a similar purpose. v

The abutment or mason-work bein in readiness with a ro er skew-back v'rooved to receive -the tendues g n v g o of the sections in place, theconstruction is commenced atlfeach e'nd' ofthe4 arch by first securing asection to each skew-back. This isdoneby-slipping the' tongues of the section in the grooves ofthe skew-back, then uniting to these respectively section by section until the whole is ready for the key-section, Which'isl then hoisted above the openV space left for it, as, shown in iig. 3,and lowered in -p1ace,rtbe abutting ends travelling in the direction hereinhefore stated, and clearly shown lin said last-mentionedigure. i i

Having thus described my invention, ivhat I claim as new, and desire to secure by Letters Patent', Aisi-4 1. Thel `construction of sections or voussoirs, consisting of abutting ends, ianges,'rib, and cross-plote, with tongues, grooves, and dove-tails, all` arranged snbstantially'ns and for the purposes specified..

f2; The construction of bridges, arches, &e., `byeon'ibining a series of sections orvoussoirs, und scouring them to cach other, substantially as herein specified'.4 '1 l A The above specification of my invention signed by me., this 15th day of June, 1867. 4

- GEO. T.4 LAPE.

Witnesses:

Psinn VAN ANrwnnP, THOMAS VAN ANTwERr. 

